Recently, liquid crystal display has been closely related with people's daily life, and the products such as liquid crystal mobile phones, liquid crystal display devices, and liquid crystal televisions have taken all or most of the market shares. Along with an increased quantity of the liquid crystal products and a wider application thereof, there is a high demand on the display quality of the liquid crystal products, such as wide viewing angle, high contrast, rapid image switching (rapid response time), low power consumption and stable images.
To obtain a stable image, one of the problems to be solved is “afterimage”. The so-called “afterimage” refers to image sticking, generally including “surface afterimage” and “line afterimage”. The essential causes for the two afterimages are the same, i.e., when a static image is maintained by a liquid crystal screen for a long period of time, liquid crystal molecules will be polarized after being driven by charges for a long period of time, so that the liquid crystal molecules cannot be deflected normally under the control of a signal voltage. In other words, even if the displayed contents are changed, traces of the static image may still be seen on the screen.
Generally, TV signals are transmitted in an interlaced scanning manner, so as to save the transmission bandwidth for the signals. The so-called interlaced scanning, contrary to progressive scanning, refers to the scanning of video display in an interlaced manner. Because the interlaced scanning is used for the TV signals while the progressive scanning is used for a LCD, with respect to the video signals transmitted in the interlaced scanning manner, it is required to reconstruct, in various ways, the missing even-numbered (odd-numbered) frame image information for odd-numbered (even-numbered) frame image information, so as to obtain a complete image signal.
A common way is to set a signal voltage for a middle row as an average value of those for the previous and next rows when the odd-numbered or even-numbered frame signals are input in the interlaced scanning manner.
The inventor finds that, serious line afterimages will occur for the liquid crystal panel with a circuit which inputs the signals in the interlaced scanning manner. These line afterimages may be removed by periodically reversing a driving signal input into a data line. However, such a method will cause an image to be flickered, especially for a static image.